[PATCH] D72594: [clangd] Include expression in DecltypeTypeLoc sourcerange while building SelectionTree

[Kadir Cetinkaya via Phabricator via cfe-commits]

kadircet created this revision.
kadircet added a reviewer: sammccall.
Herald added subscribers: cfe-commits, usaxena95, arphaman, jkorous, MaskRay, ilya-biryukov.
Herald added a project: clang.

Currently AST only contains the location for `decltype` keyword,
therefore we were skipping expressions inside decltype while building selection
tree.

This patch extends source range in such cases to contain the expression as well.
A proper fix would require changes to Sema and DecltypeTypeLoc to contain these
location information.

Fixes https://github.com/clangd/clangd/issues/250.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D72594

Files:
  clang-tools-extra/clangd/Selection.cpp
  clang-tools-extra/clangd/unittests/SelectionTests.cpp


Index: clang-tools-extra/clangd/unittests/SelectionTests.cpp
===================================================================
--- clang-tools-extra/clangd/unittests/SelectionTests.cpp
+++ clang-tools-extra/clangd/unittests/SelectionTests.cpp
@@ -323,6 +323,12 @@
             Foo x = [[^12_ud]];
           )cpp",
           "UserDefinedLiteral"},
+      {
+          R"cpp(
+        int a;
+        decltype([[^a]] + a) b;
+        )cpp",
+          "DeclRefExpr"},
   };
   for (const Case &C : Cases) {
     Annotations Test(C.Code);
Index: clang-tools-extra/clangd/Selection.cpp
===================================================================
--- clang-tools-extra/clangd/Selection.cpp
+++ clang-tools-extra/clangd/Selection.cpp
@@ -527,6 +527,16 @@
   // don't intersect the selection may be recursively skipped.
   bool canSafelySkipNode(const DynTypedNode &N) {
     SourceRange S = N.getSourceRange();
+    if (auto *TL = N.get<TypeLoc>()) {
+      // DecltypeTypeLoc only contains the SourceRange for `decltype` keyword.
+      // We are extending the SourceRange up until the end of the expression
+      // inside decltype. Note that this will not include the closing
+      // parenthese.
+      // FIXME: Alter DecltypeTypeLoc to contain parentheses locations and get
+      // rid of this patch.
+      if (auto DT = TL->getAs<DecltypeTypeLoc>())
+        S.setEnd(DT.getUnderlyingExpr()->getEndLoc());
+    }
     if (!SelChecker.mayHit(S)) {
       dlog("{1}skip: {0}", printNodeToString(N, PrintPolicy), indent());
       dlog("{1}skipped range = {0}", S.printToString(SM), indent(1));


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